BAND-3-HT, A HUMAN RED-CELL VARIANT ASSOCIATED WITH ACANTHOCYTOSIS AND INCREASED ANION TRANSPORT, CARRIES THE MUTATION PRO-868 -! LEU IN THE MEMBRANE DOMAIN OF BAND-3

1. We have studied band 3 HT, a human red-cell band 3 variant with inc reased M(r), which is associated with abnormal red-cell shape (acantho cytosis) and increased anion-transport activity. 2. We have shown that the increased M(r) does not result from the presence of the band 3 Me mphis mutation, and that the variant band 3 is covalently labelled by isothiocyanato-1,2-di-phenylethane2,2'-disulphonic acid (H-2DIDS) less readily than normal. 3. cDNA cloning studies show that band 3 HT resu lts from the mutation Pro-868 --> Leu, and the possible significance o f the mutation in the altered anion-transport activity and cytoskeleto n binding properties of band 3 HT is discussed.